(1) Gene 4 protein does not catalyze the hydrolysis of NTPs in the presence of duplex DNA, nor can T7 DNA polymerase use duplex DNA as a template.
(2) Delineation of the presence and anatomy of an obstructed, nonfunctioning upper-pole duplex system often requires multiple imaging techniques.
(3) Under optimal reaction conditions, HhaI and RsaI cleaved the DMTS-std duplex to 76-77% completion and the DMTS-imp duplex to 96-99% completion.
(4) In 29 patients undergoing duplex sonography of the hepatic artery, six (21%) had absence of a Doppler arterial pulse.
(5) Repeated transient ischemic attacks in the same territory with minimal lesions on arteriography and non-homogeneous plaque on duplex scan; 2.
(6) Depending on local anatomical properties duplex scanning failed to make a decision about the state of the ostium of the vertebral artery in 24% of the cases.
(7) The poly(dG-dC) helical duplex forms a modified, B-family structure (B*) at very high hydration and a normal B structure at slightly lower hydration.
(8) Crandell feline kidney cells in which the ADV-G strain of ADV was permissively replicating contained virion and non-structural proteins, large amounts of single stranded virion DNA, duplex replicative form (RF) DNA, and mRNA.
(9) Single-stranded linear DNAs were prepared by separating strands of duplex molecules or by cleaving single-stranded circles at a unique restriction site created by annealing a short defined oligonucleotide to the circle.
(10) Duplex and color Doppler sonography have become indispensable for evaluating the major vessels of the abdomen.
(11) In 60 patients, we examined 75 femoral bifurcations by duplex scanning and compared them with the independently performed angiography.
(12) A preoperative carotid evaluation by a Duplex Scanner ATL Mark V has been carried out in 338 patients candidates to CABG.
(13) The same six classes of hybrid duplexes were revealed when (32)P-labeled 50S virion RNA was hybridized with an excess of 18S RNA.
(14) Deep Doppler duplex imaging was supplemented with real-time spectral analysis and velocity measurements in 29 cases.
(15) The equilibrium between the loop and fully paired duplex conformations of the TATA 12-mer and TATA 16-mer is shifted toward the latter on addition of moderate salt.
(16) These leftward transcripts may antagonize the expression of the viral nuclear antigen messages by the formation of RNA duplexes.
(17) The stabilities of the duplexes are similar to those formed by unmodified oligomers, whereas the stability of the triplexes is approximately 18 degrees C lower than that formed by unmodified oligomers.
(18) Ribonuclease activity directed against the synthetic duplex polyrC:polyI was detected in nuclear extracts from both unstimulated and PHA-stimulated human lymphocytes.
(19) Our study shows that detection of a pulsatile portal venous waveform on duplex Doppler sonography in patients with liver dysfunction should raise the possibility of tricuspid regurgitation.
(20) Thus, the non-invasive duplex-sonography is a very appropriate method to diagnose thrombosis of the popliteal region and proximal.
Quadruplex
Definition:
(a.) Fourfold; folded or doubled twice.
Example Sentences:
(1) However, at a 50-fold higher strand concentration, the single-stranded oligomer is gradually converted into the quadruplex.
(2) We propose a model in which duplex or hairpin forms of G-DNA are folding intermediates in the formation of either 1-, 2-, or 4-stranded quadruplex structures.
(3) There has been much recent interest in the self-association of short deoxyguanosine-rich motifs within single-stranded DNAs to generate monovalent cation modulated four-stranded helical segments called G-quadruplexes stabilized by hydrogen-bonded G-tetrad alignments.
(4) Thus the number of T residues surrounding the dG cluster might control the rigidity of the quadruplex structure.
(5) Equilibrium ultracentrifugation studies confirm that these quadruplexes are composed of two strands of d(G3T4G3).
(6) The only precedent known (to us) for a cation-specific stabilization is that seen in the quadruplex structure formed by poly I.
(7) The quadruplex, [d(TTGGGGTT)]4, is resistant to denaturation in 7 M urea, in which the Watson-Crick type d(TTGGGGTT).d(AACCCCAA) duplex dissociates.
(8) We observe well-resolved proton NMR spectra corresponding to a G-quadruplex monomer conformation predominant at 50 mM K cation concentration and a G-quadruplex dimer conformation predominant at 300 mM K cation concentration.
(9) Our results indicate that specific differences in ionic interactions can result in a switch in telomeric DNAs between intramolecular hairpin-like or quadruplex-containing species and intermolecular quadruplex structures, all of which involve G.G base pairing interactions.
(10) The possible biological function of quadruplexes is discussed.
(11) The DNA oligonucleotide d(CGCG3GCG) can form either a Watson-Crick (WC) hairpin or a parallel-stranded quadruplex structure containing six G-quartet base pair assemblies.
(12) We find that these molecules fold to form a symmetrical bimolecular and an intramolecular quadruplex, respectively.
(13) An increase in ionic strength stabilizes the single-stranded structure, so it seems to inhibit the formation of the quadruplex.
(14) Experiments on ethidium bromide binding to the oligonucleotides have shown that the oligomer anti(A-T) exists, at a low ionic strength, as a four stranded complex ("quadruplex") contains two antiparallel helices, d(A).d(T), which have a parallel orientation and are bound to one another owing to the formation of additional hydrogen bonds between nucleic acid bases.
(15) The quadruplex is stable in the presence of 40 mM K+ at micromolar DNA concentration and can be kinetically trapped as a metastable form when prepared at millimolar DNA concentration and then diluted into buffer containing 40 mM Na+.
(16) Cations stabilize the quadruplex in the order K+ greater than Ca2+ greater than Na+ greater than Mg2+ greater than Li+ and K+ greater than Rb+ greater than Cs+, indicating that K+ has an optimum ionic radius for complex formation and that ionic charge affects the extent of ion-induced stabilization.
(17) Comparison with the corresponding CD spectral characteristics suggests that the electrophoretic intensity enhancement of the intermolecular G-quadruplex band is correlated to the intensity enhancement of of the positive CD maximum at 265 nm.
(18) Similar but less dramatic enhancement of the intermolecular quadruplex band is also observed in T4.
(19) Since K+ and NH4+ are known to stabilize a parallel-stranded quadruplex structure of poly[r(I)4], we infer that the multistranded structure is a quadruplex.
(20) UV thermal denaturation curves show a single concentration-dependent transition and provide data for quantitating the thermodynamics of quadruplex formation.